Five
to six million years ago:The
ape/hominid line splits. At that point we have an ultraprimitive
ape-man. This first bipedal primate has slightly curved hands
and toes, relatively long arms and short legs, and,
compared to an ape, smaller canine teeth and thicker dental
enamel.

Around
4.5 million years ago:
We dont know a lot about Ardipithecus ramidus, because
the findings havent been published yet. But we do know it has
smaller canines and slightly thicker enamel.

Around
4.1 million years ago:
We see Australopithecus anamensis, which Meave Leakey
discovered near Kenyas Lake Turkana. An anamensis knee
joint indicates the animal is walking upright. It has relatively
reduced canines and thicker enamel but a very small
brain and a very primitive, protruding jaw not unlike a chimpanzees.